The utilization of coal in Power Plants (PLTUs) can lead to the generation of fly ash waste, which may contain natural radionuclides that can potentially contaminate the surrounding environment. Despite Labuan PLTU's land-coastal location, marine environment monitoring remains minimal. A recent study conducted sediment and seawater sampling, revealing varying levels of natural radionuclides 226Ra, 232Th, and 40K ranging from 3.4 to 27.5 Bq kg-1, 3.9 to 34.9 Bq kg-1, and 64.0 to 275.0 Bq kg-1 in sediments, respectively. Meanwhile, the activity concentration of natural radionuclides 226Ra and 232Th in seawater ranges from 0.5 to 1.1 Bq L-1 to 0.7-1.5 Bq L-1, respectively. These findings provide baseline data for marine radiation levels around PLTU Labuan. Additionally, risk assessments were conducted, indicating Raeq, Hin, and Hex ranges of 13.80-91.00 Bq kg-1, 0.04-0.25, and 0.05-0.31, respectively. The study concludes that Labuan's radiation levels are within safe limits for exposure.